Hi Michal,
At translatewiki.net[2] we use the MediaWiki extension Translate[3] to facilitate the translation process. We import from and export to native product files. For this we have file format support components[4]. As far as I could assess, we have no problem supporting phpMyAdmin's current source format, although I have no tested yet. Output files for languages other than English will be clean (stripped of all comments). Links to some examples of supported file formats and
results below my signature.
We use comments to determine non translated messages, that might be difference when compared to your examples.
[SM] That's probably something we need to assess after we possibly decide to look further into cooperating (which I hope we will). Ideally there is no duplication.
From our perspective it is important to get an idea if phpMyAdmin and
translatewiki.net working together is something that has a chance. If so, I would like to go into more detail with one or a few of you, so we can work out the details and seek wide consensus again.
I generally think it is good idea to have a web interface. We already do have it for documentation translation (using Pootle for that) and I thought about adding support for our translations to Pootle, but never actually got to it.
[SM] So here you have an offer that requires little work from your side, on a platform with an established translators community. Now what? :) We also have a 'page translation' feature that may fit your needs for the documentation, but it is probably too early to look into that yet. Translatewiki.net can support gettext, too, though.
Cheers! Siebrand